Add greetings workflow for issues and PRs

Author: Rudra-G-23

.github/workflows/greetings.yml

@@ -0,0 +1,15 @@
+name: Greetings
+# https://github.com/marketplace/actions/first-interaction
+# https://github.com/Borda/kaggle_SandBox/blob/main/.github/workflows/greetings.yml
+
+on: [issues, pull_request]
+
+jobs:
+  greeting:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/first-interaction@v3
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          issue-message: "Hi! Thanks for your contribution on the show-file-tree Python package. Share this repo with all your friends — great first issue!"
+          pr-message: "Hey, thanks for the input! Please give us a bit of time to review it! If you like the show-file-tree Python package, share this repo with your friends!"